The current system of using Latin to name biological organisms was developed by Carl von Linne, more commonly known by his pen name Linnaeus, about 250 years ago.  (His Species Plantarum was published in 1753.)  This system is known as the Linnaean binomial system of nomenclature.  In this system, biological organisms, such as plants, are given two latinized names, the Latin binomial or so-called "scientific name".  The first name represents the


and the second name is termed the

specific epithet.

The generic name in combination with the specific epithet constitutes the species name.  Thus each species has a two part name or binomial.   The custom of using latinized names and spelling originated from medieval scholarship and the use of Latin in most botanical publications until the middle of the nineteenth century.

      In this binomial system, humans are known taxonomically as:

Homo sapiens

(Latin: homo, man; sapiens, wise or knowing; hence, "wise man" or "knowing man")

The tree species that is commonly known in North America as red maple has been given the Latin binomial of Acer rubrum.

Red Maple   =   Acer rubrum

The red maple is in the "maple" genus, which is called Acer, and its specific epithet is rubrum, which is Latin for red.  Therefore, the binomial name for this species is Acer rubrum.   Of course plants are named with reference to more or less similar plants, for example other Acer, and in doing so are placed into a number of increasingly broader taxonomic ranks or taxa (singular, taxon).  An example is shown below:


 Planta -- plants    (~326,000 species)


    Tracheobionta -- vascular plants (~287,000)


     Magnoliophyta -- angiosperms, flowering plants   (~259,000)


      Magnoliopsida -- dicotyledons   (~199,000)


       Rosidae -- flowers with separate petals   (~58,000)


        Sapindales -- woody, lobed or compound leaves   (~5,700)


         Aceraceae -- (now Sapindaceae) opposite leaves, winged samara; mostly maples   (~152)


         Acer L. -- maples   (~150)


          Acer rubrum L. -- red maple   (1)

You might argue that we should just use the so-called "common names" of plants, since it would be much simpler, especially since few people can read or speak Latin.  Thus we could all agree that the name for red maple is Red Maple, this would be an English binomial system.  However, there are problems with using common names, such as:

  • "Common names" are often common only to a localized region.  The Red Maple is commonly called the Scarlet or Swamp Maple in some areas.  The tree Nyssa sylvatica, which is native to the eastern US, has at least four common names (i.e., Sour Gum, Black Gum, Black Tupelo, Pepperidge).  In England the white waterlily has 15 common names, and if you include the common German, French, and Dutch names it has over 240 names!
  • Sometimes the same common name is used in different regions to identify completely different plants.  A plant in Georgia called ironweed is of the genus Sidai, whereas in the Midwest ironweed refers to a plant in the genus Vernonia.
  • Common names usually do not provide information on generic or family relationships, they tend to be independent of other names.  In fact common names may suggest erroneous relationships between plants.  For example, only one of the following plants is a "true cedar", i.e., of the genus Cedrus:  Japanese Cedar (Cryptomeria japonica), Port Orford Cedar (Chamaecyparis lawsoniana), Western Red Cedar (Thuja plicata), Eastern Red Cedar (Juniperus virginiana), and Deodar Cedar (Cedrus deodara).
  • Some plants, especially those that are rare, do not have common names.   Or more correctly, they lack common names in English, most may have been named by native people familiar with a given plant.

    Since we now frequently interact with people all over the globe, using a myriad of languages, a single, agreed upon name for an organism is a great advantage. Thus the success of the Linnaean binomial system.

          A Latin binomial name (the "scientific name") is italicized or underlined, the genus is capitalized and the specific epithet is usually not capitalized.  However, the specific epithet may be capitalized if it is,

    • derived from a person's name (e.g., Spiraea douglasii or Spiraea Douglasii - after David Douglas), or
    • from a vernacular name (e.g., Picea omorika or Picea Omorika - the Balkan name for spruce), or
    • from a generic name (e.g., Picea abies or Picea Abies - where Abies is the genus name of Fir).

The tree commonly known as Sugar Maple, has the scientific name Acer saccharum, but is should be written as:

Acer saccharum    or   Acer saccharum,

However, sometime you might see it written as:

Acer saccharum Marsh.   or   Acer saccharum Marsh.

The abbreviated name following the plant name (i.e., Marsh.) is the name of the "authority" or "author", the individual who first named the plant "scientifically", in this case Humphrey Marshall.  Similarly, the scientific name of the white oak is written as

Quercus alba L.

here the the letter "L" is used to identify Linnaeus as the authority.  In most nursery and landscaping literature the authority name does not accompany the scientific name.



      Sometimes it is possible to obtain offspring or progeny from crossing plants of different species, for example say two species of Maple (Acer).   Frequently a  ×  (the multiplication sign) is used in a scientific name of such hybrid plants.   The strawberry of commerce is a hybrid, the result of a chance cross between plants of two strawberry (Fragaria) species, Fragaria chiloensis and Fragaria virginiana.  The scientific name of the commercial strawberry is,

Fragaria × ananassa,

with the  ×   indicating that it is a hybrid.  (The proper designation is Fragaria ×ananassa, with no space between the × and the specific epithet, however, this sometimes causes confusion since the  ×   may be read as the letter "x".)   Occasionally plants in different genera have been hybridized, resulting in a intergeneric hybrid.  For example, English Ivy (Hedera helix) was successfully crossed with Japanese Fatsia (Fatsia japonica), and the resulting plant has the common name Fatshedera; its botanical name is

× Fatshedera lizei

   The  ×  before the genus name indicates that this plant is a hybrid of two genera.


            In his book, Botanical Latin, William Stearn, stated the following: "Botanical Latin is essentially a written language, but the scientific names of plants often occur in speech. How they are pronounced really matters little provided they sound pleasant and are understandable by all concerned.  This is most likely to be attained by pronouncing them in accordance with the rules of classical Latin pronunciation.  There are, however, several systems, since people tend to pronounce Latin words by analogy with words of their own language" (p. 53).
      An example of this difference is shown in two "authoritatve" pronunciations of Acer saccharinum, the Silver Maple:

A-ser sak-kar-I-num (American)        AY-ser sak-a-REE-num (British)

and for the David Maple, Acer davidii:

A-ser da-VID-ee-I (American)        AY-ser da-VID-ee-ee (British)

            For more information on this topic, please refer to one of Stearn's books or to an article in the magazine, Horticulture (Fisher, 2000).

Some Terms


  • Weakly defined as a more or less closely related and definable group of organisms (plants) comprising one or more species.  A genus is an aggregate of closely related species.
  • The species have more characteristics in common with each other than they do with species of other genera in the same family.  Similarity of flowers and fruits is the most widely used feature of comparison.
  • A genus may contain a single species (e.g., Ginkgo) or more than 100 (e.g., Rosa).


  • This is difficult to define, more a concept than an absolute entity.  Sometimes defined as a group of individual organisms (plants) that are fundamentally alike.
  • Ideally a species should be separated by distinct morphological differences from other closely related species.  This is necessary for a practical classification that can be used by others.
  • All the individuals in a given species are not identical.  Think of it as a population in which any character might be expressed to different degrees in each individual.  Humans are classified as the single species Homo sapiens, but we certainly are not morphologically identical.  Check this idea out by taking a stroll in the woods and examine plants of a single species.
  • Species is abbreviated sp. (singular) or spp. (plural).

Variety (Latin, varietas):

  • In the botanical sense, variety is a population of plants of a species that display marked differences in nature, and these differences are transmitted by seed (i.e., inherited).
  • Variety, abbreviated var. is subordinate to species. A variety name is written in lower case, italicized or underlined, and is preceded by the abbreviation var. For example, the common honeylocust in the wild has thorns, but thornless plants are also found. The honeylocust is

Gleditsia triacanthos

whereas the thornless honeylocust is named

Gleditsia triacanthos var. inermis.

(triacanthos = three spined, inermis = unarmed, i.e., lacking thorns ).

  • Sometimes subspecies (abbreviated ssp. or subsp.) is used in place of variety.  Their use depends upon the taxonomic "school" of the writer.

Form (Latin, forma):

  • Used to recognize and describe sporadic variations, such as the occasional white flowered plant in a normally purple-flowered species. For example: the flowering dogwood (Cornus florida) in nature usually has white flowers, but pink flowered plants occur.  They might be referred to as:

Cornus florida f. rubra

However, some might consider if a "variety" characteristic and use:

Cornus florida var. rubra.

  • The term form is apparently little used by present-day taxonomists, but it is still used in the horticultural literature.


  • A relatively modern term, coined by L.H. Bailey, derived from the term "cultivated variety".
  • It is defined as an assemblage of cultivated plants which is clearly distinguished by one or more characters, and which when reproduced (sexually or asexually) retains its distinguishing characteristics.
  • A well known cultivar of Norway Maple (Acer platanoides) is the purple leafed 'Crimson King'. So the plant would be named as follows:

Acer platanoides 'Crimson King'

            Note the single quotes on either side of the cultivar name, which in not italicized or underlined.

  • At one time the term cultivar was abbreviated as cv. and a plant could also be named as shown below (single quotes deleted). However this is no longer a valid alternative.

Acer platanoides cv. Crimson King

  • According to international rules [International Code of Nomenclature for Cultivated Plants (ICNCP)] cultivar names coined since 1959 should be in a modern language, i.e., they should not be Latin or latinised, as many were in the past.

Patents and Trademarks:

  • Patents give exclusive rights (i.e., protection) to an inventor to make, use, and sell his/her invention.  Introduced plants can be patented.  For 20 years after the date indicated on the patent, only the patent holder may commercially raise or sell a patented plant.   Others may do so through license or royalty agreements with the patent holder.

An example of a patented plant: An unusual plant was discovered in June 1968 in a large field of 120,000 seedlings of the Common or Eastern Ninebark species, Physocarpus opulifolius, growing in the Kordes Nursery, near Hamburg in Germany.  The plant had reddish foliage which contrasted markedly with the typically green foliaged plants of this speces.  The unique plant was patented as Physocarpus opulifolius `Monlo` (see below).

The following is from the U.S Patent and Tradmark Office:

United States Patent     PP11,211
Kordes, et al      February 8, 2000
Physocarpus opulifolius `Monlo`
A new and distinct selection of Ninebark, Physocarpus opulifolius, which shall be referred to hereinafter as cultivar `Monlo`.  Cultivar `Monlo` differs distinctively from other Physocarpus opulifolius plants by possessing a unique combination of an outstanding cold hardy shrub with intense foliage color throughout the seasons peaking in summer to a maroon red and contrasting to the creamy-white flowers.
Inventors: Kordes; Gunter (Bilsen, DE), Schadendorf; Hans (Ellerbek, DE)
Assignee: Monrovia (Azusa, CA)
Appl. No.: 09/006,709      Filed: January 14, 1998

  • Trademarks offer another, and simpler, form of protection.  The name of a plant can be trademarked and such names cannot be used as a name for any other similar plant or product.  Trademarked plant names are indicated by use of trademark (™) or registered trademark (®) designations (e.g., Betula nigra Heritage™) and the usage of such names is legally controlled and may continue indefinitely.  However, laws governing their usage may vary from state to state.

    Physocarpus opulifolius 'Monlo' was patented (see above) then the name, DIABOLO, was trademarked.   

    The following is from the U.S Patent and Tradmark Office:

Word Mark   DIABOLO
Goods and Services IC 031.    US 001 046. G & S: LIVE ORNAMENTAL PLANTS. FIRST USE: 19980225. FIRST USE IN COMMERCE: 19980225
Mark Drawing Code    (1) TYPED DRAWING
Serial Number    75449439
Filing Date    March 11, 1998
Current Filing Basis    1A
Original Filing Basis    1A
Published for Opposition    November 10, 1998
Registration Number    2241622
Registration Date    April 27, 1999
Assignment Recorded    ASSIGNMENT RECORDED
Type of Mark    TRADEMARK
Register    PRINCIPAL
Affidavit    Text SECT 15. SECT 8 (6-YR). SECTION 8(10-YR) 20081121.
Renewal    1ST RENEWAL 20081121
Live/Dead Indicator    LIVE

Thus these plants are now sold under the name Physocarpus opulifolius Diabolo®.  Monrovia Nursery obtained the name Diabolo® from the originator of the plant, Kordes Nursery in Germany.  The word diabolo is derived from the Latin, diabolus, and Greek, diabollos, words for devil, not the Spanish diablo.   However, the name frequently seen in nursery commerce in the US is the incorrect name Diablo, probably because of the familiarity of that name in Hispanic culture.


  • A cultivar name is considered descriptive of the plant, and it may be registered with the International Code of Nomenclature.  A trademark name cannot be used in the Code of Nomenclature .  Thus, a unique or novel name must be created in addition to the cultivar name to establish a trademark.  Trademark names are considered "brand names", similar to Air Jordan being a brand of athletic shoes, and have no taxonomic validity.  Furthermore, if a trademark name is used in international registers or printed matter as a cultivar name, the name becomes generic and losses the protection status for the inventor (breeder).
  • Thus, a trademarked plant often may have a trademark name and a cultivar name. In this case, the cultivar name is sometimes considered a "nonsense" name in that it is rarely used in commerce.   The trademark name is the name promoted commercially.  However, the so-called nonsense cultivar name is the name used in the Code of Nomenclature.
  • Nursery catalogs (and instructors) are sometimes not careful as to a plant's correct cultivar or trademark name.  These names get confused and misused, with trademarks frequently designated as cultivar names.  An example of name confusion is shown with the names for the popular Red Sunset selection of Red Maple (Acer rubrum) developed at the Frank J. Schmidt nursery in Boring, Oregon.

    This maple is trademarked Red Sunset®, hence,

Acer rubrum Red Sunset®

and its cultivar name is 'Franksred', hence,

Acer rubrum 'Franksred'

but it is sometimes incorrectly designated in nursery catalogs as,

Acer rubrum 'Red Sunset' or even Acer rubrum 'Red Sunset'®

Coombes, A.J. 1985. Dictionary of plant names. Timber Press, Portland, Ore.
Dirr, M. A. 1990. Manual of woody landscape plants, 4th Edition, Stipes Pub. Co., Champaign, Ill.
Dirr, M. A. 1998. Manual of woody landscape plants, 5th Edition, Stipes Pub. Co., Champaign, Ill.
Dirr, M. A. 2009. Manual of woody landscape plants, 6th Edition, Stipes Pub. Co., Champaign, Ill.
Fisher, T. 2000. How do you say that? A guide to pronouncing botanical Latin. Horticulture 97:41-42, 44.
Hyman, R., and R. Pankhurst. 1995. Plants and their names: a concise dictionary. Oxford University Press, New York.
Jacobson, A.L. 1996. North American Landscape Trees. 722 p., Ten Speed Press, Berkeley, Calif.
Jones, S. B., and A. E. Luchsinger. 1979. Plant systematics. McGraw-Hill, New York.
Stearn, W. T. 1973. Botanical Latin. David & Charles, Newton Abbot, England.